1. Field of the Invention
The present invention relates to popcorn and a process for producing the popcorn. More specifically, the present invention relates to popcorn in which burns or sticking of popcorns with each other is not caused during the heating step of the process and give excellent taste and palatability, and a process for producing the popcorn.
2. Discussion of the Related Art
Popcorn is obtained by thermally expanding corn, and eaten as snack foods. When the corn is heated, the adhesion to a griddle or a container or the adhesion of popcorns with each other by paste-formation of the starches in the corn along with expansion of the corn is likely to be caused. Therefore, the edible fat or oil has been used in the process of producing popcorn. The edible fat or oil has been used for the purposes of leveling thermal energy during production of the popcorn, promoting thermal retention strength, thereby aiding the thermal expansion of the corn, and preventing the adhesion to the griddle or the container or the adhesion of the popcorns with each other during the production of the popcorn.
However, since a general edible fat or oil has a weak adhesion-preventive effect, the popcorn is likely to be burned, and the popcorns easily stick with each other. If this problem were to be conventionally solved, the amount of the edible fat or oil used becomes large, so that the taste and the palatability of foods are impaired, so that satisfactory effects cannot be obtained.
Especially in recent years, popcorn foods which can be readily eaten by directly heating a heat-resisting container charged with popcorn raw materials such as corn, a fat or oil, and seasonings over a stove for households, with a microwave oven or the like, have been made commercially available. However, the popcorn foods have the problems of causing excessive use of the fat or oil and burns due to partial heating.
An object of the present invention is to provide popcorn having extremely excellent properties in preventing the adhesion, causing no burns and stickiness of the popcorns with each other, and having excellent taste and palatability, and a process for producing the popcorn.
These and other objects of the present invention will be apparent from the following description.
According to the present invention, there are provided:
[1] a process for producing popcorn comprising the steps of:
(a) mixing a polyglycerol fatty acid ester having an hydrophilic lipophilic balance (xe2x80x9cHLBxe2x80x9d) of 10 or less made from a polyglycerol having an average degree of polymerization of 2 to 6 and oleic acid, an edible fat or oil and corn as raw materials; and
(b) heating the mixture obtained in step (a) to give popcorn; and
[2] popcorn obtained by the process of item [1].
In the present invention, step (a) comprises mixing a specified polyglycerol fatty acid ester, an edible fat or oil and corn with each other.
The term xe2x80x9cpolyglycerolxe2x80x9d is a polyglycerol having an average degree of polymerization of 2 to 6, preferably 2 to 5, more preferably 2 to 4. Examples of the polyglycerol include diglycerol, triglycerol, tetraglycerol, and hexaglycerol. The term xe2x80x9caverage degree of polymerizationxe2x80x9d as referred to herein is a value which is calculated on the basis of its hydroxyl value. In addition, the lower the content of the glycerol in the composition of the polyglycerol used in the present invention, the better. When the content of the glycerol is 20% by weight or less, the resulting composition can be aptly subject to practical use. When the content of the glycerol is 5% by weight or less, it is more preferable, because the smoking amount of the polyglycerol is even smaller. In a case of a polyglycerol fatty acid ester obtained from a polyglycerol having an average degree of polymerization exceeding 6, the solubility of the polyglycerol fatty acid ester in the edible fat or oil becomes drastically poor, so that the effects of the present invention cannot be obtained.
In the present invention, the term xe2x80x9coleic acidxe2x80x9d preferably refers to one usually obtained by hydrolyzing and purifying rapeseed oil, soybean oil, palm oil, or the like, and those containing a small amount of a saturated fatty acid such as palnitic acid or stearic acid, a higher unsaturated fatty acid such as linoleic acid, or the like can be utilized depending upon the extent of the purification. When the amount of the saturated fatty acid is too large, the fluidity of the edible fat or oil becomes drastically poor, so that the effects of the present invention cannot be obtained. On the other hand, when the amount of the higher unsaturated fatty acid is too large, the flavor of the popcorn is drastically impaired due to thermal deterioration during storage and cooking, thereby making it difficult to be used for practical purposes.
In the present invention, the term xe2x80x9cpolyglycerol fatty acid esterxe2x80x9d refers to a polyglycerol fatty acid ester having an HLB of 10 or less, preferably 2 to 10, more preferably 3 to 7, which is obtained by esterification of the above-mentioned polyglycerol with the above-mentioned oleic acid by a conventional method. The polyglycerol fatty acid ester is, for instance, one or more polyglycerol fatty acid esters such as diglycerol monooleate, diglycerol dioleate, triglycerol monooleate, triglycerol trioleate, hexaglycerol dioleate, and hexaglycerol hexaoleate. When the polyglycerol fatty acid ester has an HLB exceeding 10, the solubility of the polyglycerol fatty acid ester to the edible fat or oil becomes drastically poor, so that the effects of the present invention cannot be obtained. The term HLB as used herein refers to an index for hydrophilic-lipophilic balance as determined by HLB determination method described on pages 21-23 of xe2x80x9cFood Emulsionsxe2x80x9d (edited by Kare Larsson and Stig E. Friberg published by MARCEL DEKKER INC. (1990)). The polyglycerol fatty acid ester obtained after the esterification reaction can be subjected to a purification treatment such as deacidification, a step of removing a catalyst, decoloration, or deodorization.
The amount of the polyglycerol fatty acid ester formulated is preferably from 0.1 to 10 parts by weight, more preferably from 0.5 to 10 parts by weight, still more preferably from 0.5 to 5 parts by weight, based on 100 parts by weight of the edible fat or oil. When the amount formulated is less than 0.1 parts by weight, a sufficient effect cannot be exhibited, and when the amount formulated exceeds 10 parts by weight, it is disadvantageous in costs.
In the present invention, the term xe2x80x9cedible fat or oilxe2x80x9d refers to a fat or oil used in production of the popcorn, especially to a fat or oil used when heating with a microwave oven the fat or oil together with corn in a container such as a sack. The fat or oil can be general edible fats or oils such as palm oil, rapeseed oil, corn oil, and lard oil as well as butter and various seasoning oils. In addition, as flavoring, table salt, sugars, spices, seasonings, perfumes, food colors and the like can be added to the mixture as desired.
The amount of the edible fat or oil formulated is preferably from 5 to 30 parts by weight, more preferably from 5 to 25 parts by weight, still more preferably from 10 to 25 parts by weight, based on 100 parts by weight of the corn in a dry state. When the amount of the edible fat or oil formulated is less than 5 parts by weight, the popcorn is adhered to a griddle, a container, or the like, and the popcorns are likely to stick with each other and burns are likely to be caused. When the amount formulated exceeds 30 parts by weight, the edible fat or oil sticks to popcorn, and the popcorn having excellent taste and palatability cannot be obtained because the flavor of the fat or oil is too strong.
In the present invention, the term xe2x80x9ccornxe2x80x9d is generally a seed of corn used for popcorn, and is not particularly limited.
In step (a), each of the polyglycerol fatty acid ester, the edible fat or oil and the corn can be separately mixed, or alternatively, the edible fat or oil previously containing the polyglycerol fatty acid ester can be mixed with the corn. The edible fat or oil containing the polyglycerol fatty acid ester is mixed in an amount of preferably from 5 to 30 parts by weight, more preferably from 5 to 25 parts by weight, based on 100 parts by weight of the corn in a dry state.
Further, in step (a), in addition to the polyglycerol fatty acid ester, it is preferable to mix lecithin, methyl silicone or a mixture thereof with the mixture.
In the present invention, the term xe2x80x9clecithinxe2x80x9d refers to one obtained by purifying from soybean, egg yolk, rapeseed or the like to be obtained as soybean lecithin, egg yolk lecithin, rapeseed lecithin or the like, which can be subjected to a purification treatment such as delipidation, decoloration, or deodorization.
The amount of the lecithin formulated is preferably from 0.1 to 5 parts by weight, more preferably from 0.5 to 5 parts by weight, still more preferably from 0.5 to 3 parts by weight, based on 100 parts by weight of the edible fat or oil. When the amount of the lecithin formulated is less than 0.1 parts by weight, its effects cannot be sufficiently exhibited. On the other hand, when the amount formulated exceeds 5 parts by weight, it is undesirable because the popcorn is likely to be colored, smoked or burned.
In the present invention, the term xe2x80x9cmethyl siliconexe2x80x9d refers to a dimethyl polysiloxane, which is usually obtained as a silicone resin or a silicone oil, and its production steps are not particularly limited.
The amount of the methyl silicone formulated is preferably from 0.0005 to 0.005 parts by weight, more preferably from 0.0007 to 0.005 parts by weight, still more preferably from 0.001 to 0.005 parts by weight, based on 100 parts by weight of the edible fat or oil.
Each of the lecithin, methyl silicone or a mixture thereof can be separately mixed with corn, or alternatively, each can be contained in the edible fat or oil together with the polyglycerol fatty acid ester to mix with corn. The edible fat or oil containing these ingredients is mixed in an amount of preferably from 5 to 30 parts by weight, more preferably from 5 to 25 parts by weight, based on 100 parts by weight of the corn in a dry state.
In the present invention, step (b) comprises heating the mixture obtained in step (a).
In step (b), the heating means is not particularly limited, as long as the corn can be thermally expanded. For instance, when the corn is placed in a grain expansion machine comprising an iron pot and a freely openable lid made of a packing material, heat can be applied at 200xc2x0 to 240xc2x0 C. for 20 to 120 seconds. When the corn is placed on a heat-resisting dish such as metal flying pan and directly heated with a stove or the like, heat can be applied at 170xc2x0 to 200xc2x0 C. for 2 to 10 minutes. When the corn is placed in a paper container or the like, heat can be applied with a microwave oven at an output of 500 to 600 W for 2 to 10 minutes.
The edible fat or oil used in present invention has a fat or oil film-forming ability even when used alone. However, when the edible fat or oil contains the polyglycerol fatty acid ester, the extensibility of the edible fat or oil over the popcorn surface becomes excellent, whereby a further strengthened fat or oil-film forming ability can be obtained. Therefore, in the popcorn of the present invention produced by mixing the edible fat or oil and the polyglycerol fatty acid ester, with corn, the fat or oil containing the polyglycerol fatty acid ester thinly and evenly forms a fat or oil film over the popcorn surface, so that the adhesion of the popcorn to a griddle or a container, and the adhesion of popcorns with each other are suppressed, whereby the popcorns are not burned nor the popcorns stick to each other.
In addition, since the edible fat or oil contains the polyglycerol fatty acid ester, the amount of the fat or oil used during the production of popcorn can be reduced, so that the oxidative deterioration odor of the oil caused by heating or storage can be reduced, whereby the taste of the popcorn is not impaired and excellent palatability can be enjoyed for a long period of time.